The Project Pad

Anyone have tuning experience with injector lag? Been having an issue with my truck on these Ford 24 lbs injectors. Stock is 18 lbs/hr and went to the 4-hole.

I found an injector lag table and have adjusted it accordingly to the Ford specs.

However on my 3000-4000 rpms at WOT, I can not get the truck past 14.0:1 AFRs. Any other RPM range it is fine. These trucks with similar configurations should be close to 12.8 afrs for max torque afik.

Regardless how how high I set the injector MS (SCT is in uS), my AFRs do not change in this range. Suggestions or ideas to chase after? Truck pulls hard as it is.

WOT timing from 3k-4k is 27 @ 3k and I dropped it down to 26 @ 4k

It does seem the throttle response is snappier since I adjusted the lag tables but no change in AFRs
I use SCT if anyone is familiar with it.

AngryTaco wrote:Anyone have tuning experience with injector lag? Been having an issue with my truck on these Ford 24 lbs injectors. Stock is 18 lbs/hr and went to the 4-hole.

I found an injector lag table and have adjusted it accordingly to the Ford specs.

However on my 3000-4000 rpms at WOT, I can not get the truck past 14.0:1 AFRs. Any other RPM range it is fine. These trucks with similar configurations should be close to 12.8 afrs for max torque afik.

Regardless how how high I set the injector MS (SCT is in uS), my AFRs do not change in this range. Suggestions or ideas to chase after? Truck pulls hard as it is.

WOT timing from 3k-4k is 27 @ 3k and I dropped it down to 26 @ 4k

It does seem the throttle response is snappier since I adjusted the lag tables but no change in AFRs
I use SCT if anyone is familiar with it.

The opening time table (I believe what you're tweaking) will have very little influence on fuel flow at high loads/high pulsewidths, as any discrepencies in opening time have a very small percentage impact on fuel delivered. At idle and low loads it is a different story--with small injectors like that, it is likely VERY low loads that you would notice a difference. You need to be adjusting the main fuel map, as the VE of the engine has likely changed with all the mods you've done.

Sam

Yeah I have adjusted those too. I have almost tripled the factory fuel ms times and no change. Someone suggested I check my fuel pressure because even the factory 18 lbs/hr should be able to handle what I've done.